PCP deals with an incoming connection (with its MAP opcode) and with timeouts of a connection (with its PEER opcode). As they are, those don't seem to help much a subscriber choosing some network services function for their traffic. MAP does have a FILTER option, which provides some filtering (ACL) capabilities, but I expect i2nsf is looking at more advanced functionality than that?
(CC’ed PCP group and MIDCOM group for wider review. )
After studying RFCs/Charter of MIDCOM and PCP, it seems to me that PCP is a lot more closely tied with MIDCOM than I2NSF.
The PCP working group is chartered to standardize a client/server Port
Control Protocol (PCP) to enable an explicit dialog with a middlebox
such as a NAT or a firewall to open up and/or forward TCP or UDP port,
regardless of the location of that middlebox”
MIDCOM “focuses its attention on communication with firewalls and network address translators (including translation between IPv6 and IPv4).”
I noticed that the detailed protocols developed by MIDCOM is quite different from PCP. For example, the MDCOM protocol is tied closely with the SIP agent (SIP/RTSP Proxy) to send “INVITE”, respond to “180Ringing” or “Port-BIND” reply to
The MIDCOM protocol is very much SIP protocol oriented, whereas the PCP is more FW/NAT device oriented.